Drilling bit



June 9, 1931. ca. 0. OLIVER 1,809,351

DRILLING BIT Filed June 26. 1929 3 Sheets-Sheet 1 IN VEN TOR.

QC. OL/VEI? Patented June 9, 1931 f UNITED STATES,

PATENT OFFICE 'G'U'Y GABLTON CF WHITTIER, CALIFORNIA, ASSIGNOR OF ONE- HAIF TO ROLAND B. GRUM, OF NEITOS, CALIFORNIA DRILLING- 311 Application filed June 26,

This invention relates to drilling bits. The general object of this invention is to provide an improved drilling bit.

A more specific object of the invention is b A further object of the invention is to provide a bit having pairs of opposed cutting.

members'thereon with a pair of said members extending throughout the full diameter of the bit and with another pairof members having their outeredges disposed within the cutting peri hery of the others.

Another 0 ject of the invention is to provide a drillingbit wherein the drilling members have an angular clearance from the front to the rear of the blade and wherein the rear is lower than the front.

Another object of the invention is to provide a curved drilling bit wherein the leading face of the blade cuts to one diameter 2 and wherein the sweep of the blades cuts to a lesser diameter.

Another object of the invention is to provide a drilling bit including a plurality of independent cutting surfaces so arranged that the opposed cutting surfaces are similar and wherein the terposed cuttingsurfaces. are similar but 0 a different size from the first surfaces.

Another object of the invention is to provide a drill having a fixed curved cutting blade wherein the curvature of the blade is struck with a radius differing from the radius of the hole which the bit makes.

' Another object of the invention is to provide a drilling bit having a plurality of cutting members comprising teeth having trailing wings so arranged that the trailing portion performs the cutting functions where the preceding portion leaves of.

. 4 Other objects and the advantages of this ing the bit in service position.

1929. Serial No. 378,888.

invention will be apparent from the following description taken in connection'with the accompanying drawings wherein: b tFig. 1 is a sideelevation of my improved Fig. 2 is a bottom shown in Fig. 1.

Fig. 3 isa cross section of my bit taken on line 3--3 of Fig. 1. p

Fig. 4 is a view similar to Fig. 2 showing the manner in which the blades cut.- 7 Fig. 5 is a View similar toFig. 3 of a modification of my invention wherein the bit includes a core drill, and

Fig. 6 is a bottom plan view of the drill 9 plan view of the bit shown in Fig. 5.

Referring to the drawings by reference characters I have indicated my improved bit generally at 10. As shown this bit comprises a body portion 12 having integral wings 13 extending therefrom in cruciform shape. Within the body 12 I provide a recess 14 which is partly threaded asat 15 for secur- On each of the wings 13 I show two cutting blades 16 although the number of blades maybe varied as desired. These blades extend transversely of the wing and include cutting faces 17 and trailing cutting faces 18. The front faces 17 have cutting edges 17. Each of the blades 16 is so formedthat the trailing edge 19 thereof is .closer to the longitudinal axis of thebit than the cutting face 17, thus cutting edge 17' and the face 17 cut one portion of the formation while the V811 trailing cutting face 18 cuts another porgion if the formation as clearly shown in -The cutting edge 17 of the face 17 is so formed that' the outer end of the edge is in advanceof the inner end of the edge when the device is rotated in an operative direction.

The cutting faces 18, which are in reality bottom faces, of each blade taper upwardly '90 towards the trailing edge while the face 18 also extends inwardly. The blades on the outer face are tapered as at 20 to form a relieved portion.

By roviding the various tapers on the blades 16 the cutting surfaces thereof are self sharpening which assures a highly efficient operation of the bit.

The blades are shown as curved but may be straight if desired, although I now prefer the curved blade.

As shown the outer blades 16 on opposed wings 13 are evenly spaced from the axis of the bit and the inner blades 16 are also evenly spaced from the axis. The blades 16 and 16 are also evenly spaced but the latter blades arenearer the axis than arethe blades 16 and 16 respectively. Thus the blades on opposed wings cut one portion of.

the formation and the blades on the wings at right angles thereto out another portion of the formation as clearly shown in Fig. 4.

It will be understood however, that other spacing of the blades 16 may be employed, such as spacing all the blades a different distance from the longitudinal axis of the bit so that they all cut different portions of the formation.

On the bottom. of one of the wings 16 I may provide a fish tail bit 22 which is of conventional form and includes cutting surfaces 23 adapted to cut the formation not cut by the inner blades 16 as shown in Fig. 4.

In the body portion 12 I provide a plurality of apertures 24 which are positioned intermediate the wings 13 and form passage: ways from the recess 14 to the exterior of the body for the passage therethrough of the circulating fluid.

In Figs. 5 and 6 I have indicated generally at 25 a slight modification of my bit wherein in place of the fish tail bit 22 I provide a core drill indicated at 26. As shown the core drill 26-includes a plurality of bpttom cutting teeth 27 surrounding an aperture 28. which communicates with the recess 14 in the body 12. A portion of the aperture 28 adjacent the recess 14 is threaded as at 20 to receive similar threads on a core barrel 30 to removably secure it thereto. Positioned outside of the bottom teeth 27 I provide a plurality of blades 32 which are preferably arranged one on'each wing, and include a cutting edge face 33 and a bottom cutting surface 34. The outermost edge of the face 33 of each of the blades 32 is preferably in advance of the rest of the face when the device is rotated in an operative direction and the outermost or advanced edge of the faces 33 of the blades 32 is preferably on the same plane as the advance edges of the faces 17 of the blades 16 on the corresponding wing when the plane is taken from the longitudinal center of the bit to the outermost edge of the'face'17 of the outer blade 16.

tudinal axis of the bit and the blades 16 cut the formation not previously cut by the teeth 27 and the blades 32.

From the foregoing description it will be apparent .that I have provided a novel drill ing bit which is simple in construction and highly eflicient in operation.

1I-Iaving thus described my invention, I 0 mm:

1. In a drill bit, a body, wings on said body, said wings comprising a plurality of pairs, with the wings of each pair arranged on opposite sides of the axis of said body, a plurality of arcuate cutting blades arranged in spaced relation on each wing, said blades having a front cutting edge and a narrower trailing cutting portion, said front cutting portion being disposed farther from the axis of said bit than the said trailing portion.

2. In a drill bit, a body portion, wings on said body, said wings being arranged in cruciform shape, a plurality of cutting blades arranged on each of said wings, and extending transversely thereof, said cutting blades depending from said wings and extending below the bottom of said body portion, the lower face of said cutting blades being arranged in a plane which inclines upwardly towards the axis of said bit and which inclines upwardly towards the trailing end of said blades, said cutting blades on opposed Wings being evenly spaced from the longitudinal axis of said bit with one set of blades closer to the longitudinal axis of said bit than the other set of blades.

3. In a drill bit, a body portion, wings on said body, said wings extending beyond the outer periphery ofsaid body and being arranged in cruciform shape, a plurality of cutting blades arranged on each of said wings and extending transversely thereof, said cutting blades depending from said wings and extendin below the bottom of said body portion, the ower face of said cutting blades being arranged at an obtuse angle relative to the longitudinal center of said bit, each of said cutting blades including a cutting edge with the lower face of said cutting blades being tapered upward from said cutting face towards the rear of said blades, a portion of portion and wings on said body, said wings comprising a plurality of pairs, with the .wings of each pair arranged on opposite sides of the axis of said body, a plurality of arcuate cutting blades arranged in spaced relation on each wing and extending transversely thereof, said blades having a front cutting edge and a narrower trailing cutting portion, said front cutting portion being disposed farther from the axis of said bit than the said trailing portion, the front edge of each blade being disposed farther from the top of said bit than the trailing portion, the blades of one pair of wings being adapted to cut one zone of formation and the blades of another. pair being adapted to cut a difierent zone of formation.

5. In a drill bit, a body portion, wings on said body, said wings extending beyond the outer periphery of said body and being arranged in cruciform shape, a plurality of cutting blades arranged on each of said wings cutting and extending transversely thereof, said cutting blades depending from said wings and extending below the bottom of said body portion, each of said cutting blades including a edge with the lower face of said cutting b ades tapered upward from said-cutting edge towards the rear of said blades, a portion of the outer face of said blades on the rear thereof being relieved, said cutting blades on opposed wings being equally spaced from the longitudinal axis of said bit and being spaced a different distance from the longitudinal axis of said bit from those on the Wings which are at right angles thereto and a fish tail bit on the lower end of said body and spaced from said cutting blades.

6. In a drill bit, a body, wings on said body, said wings comprising a plurality of pairs, with the wings of each pair arranged on opposite sides of the axis of said body, one pair of wings having a plurality of cutting blades arranged in spaced relation thereon, a. cutting blade on each of the remaining wings, said first mentioned cutting blades having a front cutting edge and a narrower trailing cutting portion, the front cutting portion of certain blades being disposed farther from the axis of said bit than the trailin cuttin portion.

In a rill bit, a body portion, wings on said body, said wings bein arranged in cruciform shape, a plurality 0 cutting blades arranged on said wings, and extending transversely thereof, said cutting blades including a front cutting portion and a trailing portion, said cuttin blades depending from said wings and exten ling below the bottom of said body portion, the lower face of said cutting blades being arranged in a plane which inclines upwardly towards the axis of said bit and which inclines upwardly towards the trailing end of said blades, said cutting blades on opposed wings being evenly spaced from the longitudinal axis of said bit, with one set of blades closer to the longitudinal axis of said bit than the other set of blades.

In testimony whereof, I hereunto aflix my signature.

GUY CARLTON OLIVER. 

